Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B37/00—Nuts or like thread-engaging members
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B39/00—Locking of screws, bolts or nuts
  • F16B39/02—Locking of screws, bolts or nuts in which the locking takes place after screwing down
  • F16B39/04—Locking of screws, bolts or nuts in which the locking takes place after screwing down with a member penetrating the screw-threaded surface of at least one part, e.g. a pin, a wedge, cotter-pin, screw
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R11/00—Individual connecting elements providing two or more spaced connecting locations for conductive members which are, or may be, thereby interconnected, e.g. end pieces for wires or cables supported by the wire or cable and having means for facilitating electrical connection to some other wire, terminal, or conductive member, blocks of binding posts
  • H01R11/11—End pieces or tapping pieces for wires, supported by the wire and for facilitating electrical connection to some other wire, terminal or conductive member
  • H01R11/26—End pieces terminating in a screw clamp, screw or nut
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R4/00—Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation
  • H01R4/28—Clamped connections, spring connections
  • H01R4/30—Clamped connections, spring connections utilising a screw or nut clamping member
  • H01R4/302—Clamped connections, spring connections utilising a screw or nut clamping member having means for preventing loosening of screw or nut, e.g. vibration-proof connection
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R4/00—Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation
  • H01R4/58—Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation characterised by the form or material of the contacting members
  • H01R4/64—Connections between or with conductive parts having primarily a non-electric function, e.g. frame, casing, rail
  • H01R4/646—Connections between or with conductive parts having primarily a non-electric function, e.g. frame, casing, rail for cables or flexible cylindrical bodies
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
  • H02G15/00—Cable fittings
  • H02G15/02—Cable terminations
  • H02G15/04—Cable-end sealings

Definitions

• the present invention relates to ah electrical earthing nut.
• SWA steel wire armoured
• banjo washer In order to comply with safety regulations in many jurisdictions it is necessary to earth at least one end of the cable. To achieve this, a particular type of washer - known as “banjo washer” - is placed under the nut, and a bolt is then drilled through a hole in the arm of the washer to receive an earth wire employing a crimped connector. Also the arm is usually bolted through the box or appliance wall.
• the arm can break if bent away from the box or appliance wall. This has resulted in a disconnection of the gland from the earth connection. This was dangerous and could result in an earth fault.
• An object of the invention is therefore to provide an earthing nut which overcomes the aforementioned disadvantages.
• Another object of the invention is to provide an earthing nut which can replace the existing combination of a nut and banjo washer on SWA cable glands.
• a further object of the invention is to provide an earthing nut which can be used in other existing electrical installations, such as other metal cable glands and electrical conduits, and may be retrofitted into such electrical installations.
• an electrical earthing nut comprising:
• a nut body having an internal thread and an external perimeter shaped to receive a tensioning device, such as a spanner, said nut body having opposing generally planar faces,
• the or each raised rib is ideally dimensioned and arranged to scrape or cut the surface against which a planar face of the nut is to abut.
• the or each, threaded aperture extends into the nut body from a perimeter of the nut body.
• the nut may have a raised or extended annulus or flange defined around the rim or aperture defined on the or each planar surface of the nut.
• three apertures are ideally provided, one to receive a bolt and the other two for receiving grub screws to drive against, or bite into, a threaded shaft on which the nut is threaded.
• the holes may be offset.
• At least three and preferably four (or more) raised projections or ribs are provided. These projections or ribs are ideally formed on a planar face of the nut.
• the outer perimeter of the nut is generally circular with opposing flat portions to receive a spanner or wrench.
• the outer perimeter of the nut is polygonal or ideally hexagonal.
• the nut may have a raised or extended annulus or flange defined around the rim or aperture defined on the or each planar surface of the nut.
• An advantage of the embodiment having the raised or extended annulus is that the nut is centralised in the event it is located in an oversize hole. This feature thus ensures the nut is held stationery, by way of an axial or compressive force, and does not vibrate. Vibration of connectors, particularly safety connectors is undesirable because contacts and connections may work loose, thus rendering the safety connector ineffective.
• the invention also extends to an earthing nut as defined above in combination with cable gland.
• the invention also extends to an earthing nut, as defined above, in combination with an electrically conductive cable.
• Methods of forming the nut include: stamping, swaging and forging. It will be appreciated that this further aspect of the invention also extends to the other preferred features associated with the above mentioned aspects of the earthing nut.
• Figure 1 shows a perspective view of a nut in accordance with one aspect of the invention
• Figure 2 shows an exploded perspective view of a cable gland and an embodiment of a nut in accordance with one aspect of the invention
• Figures 3a, 3b and 3c show plan and elevation views of three alternative embodiments of the invention.
• Figure 4 shows plan and elevation view of a further alternative embodiment of the invention, which includes an annulus.
• FIG. 1 there is shown an electrical earthing nut 1.
• Nut 1 has an annular nut body 2 with generally circular perimeter with opposing flat portions 3A, 3B to receive a spanner or other tensioning device, Nut body 2 has an internal thread 4 to receive a threaded shaft. Nut body 2 has opposing generally planar faces 5 and 6. Three radially spaced threaded apertures 7A, 7B, 7C extend into the nut body 2 from the nut body perimeter. Aperture 7A receives a bolt 8A and earth connector 8B with a wire leading to earth. Apertures 7B, 7C (which may be located at any position around the perimeter of the nut) each receive grub screws 8C, 8D to engage with, or bite into, a. threaded shaft (not shown) on which the nut 1 is placed.
• teeth 9A, 9B, 9C, 9D are provided on planar face 5 to scrape or cut into a surface against which the nut is to abut.
• the purpose of these ribs or teeth 9A, 9B, 9C, 9D is to
• Cable gland 10 to be fitted through an aperture 21 of a wall 20 of an electrical box or appliance (not shown) using the earthing nut 1.
• Cable gland 10 is of a type well known in the art having a threaded shaft 11 extending one side of a nut 12 and a compression base 13 which receives a compression nut 14.
• shaft 11 is passed through aperture 21 and secured to wall 20 by nut 1 of the invention on the other side of wall 20.
• gland 10 and nut 1 can be tightened merely by rotating gland nut 12 with a spanner or wrench (not shown). That is, a separate spanner is not required to hold nut 1 whilst gland 10 is rotated.
• Connector 8B is attached to nut body 2 by bolt 8A. This arrangement provides a more reliable mechanical and electrical connection to earth than was previously achieved with a banjo nut. Furthermore there is no longer any need for difficult drilling of a hole in the wall of a box or appliance.
• Grub screws 8C, 8D engage with and bite into shaft 11 to help ensure the nut 1 stays in close contact with the shaft 11. Grub screws aid electrical contact if used on plastic enclosures or when terminating cables (not shown) where no enclosure wall is used.
• nut 1 may be used in other electrical installations such as connecting electrical conduits into walls of domestic or industrial electrical boxes or appliances; connecting electrical leads to vibrating systems, such as engines; aeronautic or marine applications where good electrical connections and insulation are essential for safety; and oil field, chemical or petrochemical plants, where safety issues are also paramount.
• the invention may take a form different to that specifically described.
• the outer perimeter of the nut body 2 may be polygonal, hexagonal.
• Nut 1 may be sold on its own or in combination with cable gland 10. The invention thus also extends to an earthing nut as defined above in combination with cable gland.
• Figures 3a, 3b and 3c show plan and elevation views of three different sized nut 1 of an alternative embodiments of the invention, in which like parts bear the same reference numerals as in Figures 1 and 2.
• the nut shown in Figures 3a, 3b and 3c is in the form of a conventional hexagonal nut.
• Figures 3a and 3b show different sizes of nut 1 having a single hole in three sides. The reason for forming a hole in three sides is so that when the nut 1 is tightened there will always be a side, facing an operator, with a hole presented for receiving the grub screw 8.
• Figure 3c shows a larger version of the nut 1 in which two holes 7A are formed in one of the faces.
• the holes 7A are offset so as to enable the nut to be readily used in areas of limited access or fitted in applications where space is cramped, thereby always ensuring a hole is accessible for receiving a grub screw.
• the raised or extended annulus 30, in use, ensures that the nut 1 is centralised in the event it is located in an oversize hole or location where it is prone to vibration (not shown).
• Rim or annulus 30 therefore ensures the nut 1 is held stationery, by way of an axial or compressive force, and does not vibrate.
• the nut is formed from a material with good mechanical and electrically conductive properties.
• a metal such as brass or steel is preferred, however, it is envisaged that composite materials may also be used for specialist applications.

Landscapes

• General Engineering & Computer Science (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Installation Of Indoor Wiring (AREA)
• Control Of Motors That Do Not Use Commutators (AREA)
• Motor Or Generator Frames (AREA)
• Gripping Jigs, Holding Jigs, And Positioning Jigs (AREA)
• Cable Accessories (AREA)
• Transmission Devices (AREA)
• Connections By Means Of Piercing Elements, Nuts, Or Screws (AREA)
• Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
• Discharge Heating (AREA)
• Laying Of Electric Cables Or Lines Outside (AREA)
• Details Of Connecting Devices For Male And Female Coupling (AREA)
• Bolts, Nuts, And Washers (AREA)
• Conductive Materials (AREA)
• Electrotherapy Devices (AREA)
• Patch Boards (AREA)

Priority Applications (12)

Applications Claiming Priority (2)

Publications (1)

Family

ID=33042297

Family Applications (1)

Country Status (18)

Cited By (2)

Families Citing this family (16)

Citations (4)

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• 2004
  • 2004-08-19 GB GB0418497A patent/GB2417367A/en not_active Withdrawn
• 2005
  • 2005-08-19 US US11/660,264 patent/US7713071B2/en not_active Expired - Lifetime
  • 2005-08-19 PT PT05776245T patent/PT1790053E/pt unknown
  • 2005-08-19 BR BRPI0514117-6A patent/BRPI0514117A/pt not_active IP Right Cessation
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  • 2005-08-19 ES ES05776245T patent/ES2361556T3/es not_active Expired - Lifetime
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  • 2005-08-19 UA UAA200702820A patent/UA86095C2/uk unknown
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  • 2005-08-19 DE DE602005026537T patent/DE602005026537D1/de not_active Expired - Lifetime
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  • 2005-08-19 JP JP2007526572A patent/JP2008510285A/ja active Pending
  • 2005-08-19 RU RU2007109822/09A patent/RU2335052C1/ru active
  • 2005-08-19 AT AT05776245T patent/ATE499734T1/de active
  • 2005-08-19 ZA ZA200701141A patent/ZA200701141B/xx unknown
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• 2007
  • 2007-03-09 NO NO20071284A patent/NO334165B1/no not_active IP Right Cessation

Patent Citations (4)

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